Three-time Olympics veteran Eamon Sullivan said the team was taken aback by the intensity of the experience.
"As much as you think you're ready for it, the difference between world championships and the Olympics is a hundred times more pressure," he told media in Sydney.
"We under-prepared for the expectations of the pressure and the experience of the Olympics and, unfortunately, it's a bad time to learn lessons.
"But for the next Olympics, if it's the same team, it'll be a different result."
After facing intense criticism for a perceived failure to bring home as many gold medals as expected, 4x100m freestyle gold medallist Cate Campbell said Australia's expectations for gold may be too high.
"We've been obsessed with gold and other medals have lost their value," she said.
"I can't see the shame in having one other person in the entire world beating you.
"It's a tough field out there - everyone is racing incredibly fast, the world has taken a gigantic leap in swimming, we're seeing world records from the supersuits being broken, which lots of us thought wouldn't happen in our lifetimes, and it's happened in a few short years."
Sullivan said other countries stepped up and put in performances that "caught us napping", but added that negative media got to some of the younger members of the squad.
"The younger guys do read the media and take it to heart; it can really affect their emotional state and makes it hard to get back up when it feels like everyone's against you," he said.
"At the end of the day, we did the best we could. That's all we could ask for."